Focused stream, aerated foam projecting nozzle including fixed wand system and method as well as possibly portable center pointing nozzle

ABSTRACT

The invention includes components and methodology for fixed and semi-fixed systems for extinguishing fire in large industrial flammable liquid storage tanks, including aerated foam projecting nozzles discharging substantially focused streams together with aeration chambers and risers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 16/797,745,filed Feb. 21, 2020, which is a continuation of application Ser. No.15/475,429, filed Mar. 31, 2017, which is a divisional of, is related toand claims priority to, application Ser. No. 13/261,639, of same nameand same inventors, filed Apr. 16, 2013 as a national stage applicationof PCT/US11/01769, filed Oct. 17, 2011 and which claims priority to fourprovisional applications by the same inventors: Application Nos.61/455,367, 61/461,413, 61/463,296 and 61/519,071 filed Oct. 19, 2010,Jan. 8, 2011, Feb. 14, 2011 and May 16, 2011 and entitled “Rapid TankResponse, Equipment and Methodology;” “A Point and Shoot System(including as previously filed), An Ambush System and Method and aHollow Point System and Method, all for Fighting Industrial TankHazards;” “Further Developments—Fixed System (Point and Shoot, Ambushand Hollow Point),” and “Fixed/Semi-Fixed Aerated Foam Systems forIndustrial Tank Hazards,” respectively. These applications are allherein and hereby incorporated by reference in their entirety to theextent permitted by law and regulation.

FIELD OF THE INVENTION

The field of this invention lies in fixed and semi-fixed systems for theassistance of fire extinguishment and/or for addressing hazards and/orvapor suppression in industrial storage tanks, being particularly suitedfor large (at least greater than 60 foot diameter) industrial tanksstoring flammable liquids and hydrocarbon products and the like. Suchtanks may be more particularly differentiated by whether or not theyhave a fixed roof. The field of the invention lies in fire fightingnozzles for large industrial tanks, and more particularly in focusedstream aerated foam projecting nozzles capable of projecting firefighting foam in a substantially focused stream. The field of theinvention lies in fixed and semi-fixed nozzle systems and methods forextinguishing fire in large industrial tanks, and more particularly, infixed wand systems plus fixed center pointing nozzle(s) or a portablepoint and shoot monitor and nozzle system and method.

BACKGROUND OF THE INVENTION Industry Background

Williams Fire and Hazard Control, Inc. (Williams) has been a leader inthe design, development, and production of specialty firefightingequipment and methodology for use on large industrial tank fires. Astudy published in a report by SP Fire Technology in 2004, written byHenry Persson and Anders Lonnermark, stated:

-   -   Despite the lack of large-scale tank fire tests in the last 15        to 20 years, significant improvements have been made regarding        tank fire fighting using mobile equipment. The pioneers in this        development have been Williams Fire & Hazard Control Inc. (WFHC)        drawing attention to the need for solving the logistics during a        fire and to use relevant tactics. By using large capacity        monitors, large diameter hose and foam concentrate stored in        bulk containers, the logistics become manageable. The use of        large-scale monitors has also made it possible to achieve        sufficiently high application rates in order to compensate for        foam losses due to wind and thermal updraft. Williams have also        introduced the “Footprint” technology where all the foam streams        are aimed towards one single landing zone on the fuel surface,        resulting in a very high local application rate making the foam        spread more rapidly and efficiently. One of the main factors in        achieving an efficient extinguishment, according to Williams, is        the use of a high quality foam, suited for tank fire protection        and until recently, they were primarily using 3M AFFF/ATC. Due        to 3M's withdrawal from the foam business a similar foam type is        now used, manufactured by Ansul. “Thunderstorm ATC.” In 1983,        Williams extinguished a 45.7 m (150 ft) diameter gasoline tank        in Chalmette, La. (“Tenneco fire”), which at that time was the        largest tank ever extinguished using mobile equipment. A new        record was set in 2001 when an 82.4 m diameter (270 ft) gasoline        tank was extinguished in Norco, La. (“Orion fire”). The concept        for tank fire fighting used by Williams has been shown to be        successful in many other fires [35] and the concept has also        been successfully used by other companies, e.g. during the        Sunoco fire in Canada 1996.”        (Note: Thunderstorm™ foam concentrates are now developed and        produced by Chemguard Inc.) Historical Development

Historically, Williams has specialized in mobile equipment andmethodology. “Fixed system” approaches to large tank fires,historically, have demonstrated limited success in the industry as wellas high cost.

On the one hand, for “rim seal fires” (fire around the rim of a tankfloating roof, around the roof seal), traditional fixed systemapproaches place a large number of “foam chambers” or “foam pourers”around the perimeter of the storage tank, every 40 feet or every 80 feetdepending upon whether the “foam dam” on the floating roof is 12″ or 24″high. These devices drop or “pour” highly aerated fire fighting foamdown the tank wall into the tank “periphery,” or area between the tankwall and the “foam dam” on the floating roof, by force of gravity. Thecost for such system is high.

On the other hand, for “full surface liquid tank fires” in 100 foot plusdiameter tanks, proven fixed systems have not existed. That is, to theinventor's best knowledge, no fixed system has put out a fully engagedfull surface liquid tank fire in a 100 foot plus diameter tank.

Williams Fully Portable Systems

“Rim Seal Fire”

Before the “Daspit Tool,” Williams successfully used fully portabledevices and methods to extinguish “rim seal fires,” using a two partattack. In the first phase of the Williams attack a fire fighterapproached the tank and hung a portable device (foam wand with anon-reactive nozzle design) over the top edge of the tank proximate aplatform or landing. The wand largely dispensed foam directly under thedevice, suppressing the fire in the immediate vicinity, over a 30 to 40foot length. After a “beachhead” was established, a “beachhead” of 30 to40 feet of tank rim with no flames under a landing, fire fightersmounted the tank wall using the ladder leading to the landing, andcarried up handheld nozzles and hoses. (The gpm's of handheld nozzlesare roughly limited to 60 gpm for a one person nozzle and a 125 gpm fora two person nozzle.) These nozzles were the primary fire extinguishingtools for the seal fire. Having gained access to the top of the tankwall through use of a foam wand, the fire fighters extinguished the“seal fire” by walking the “wind girder” around the tank wall, using theportable nozzles in a known manner.

Daspit Tool System

Subsequently, Williams developed a Daspit tool, a portable base foraffixing a portable nozzle and monitor to the top of a tank rim or wall.With the Daspit tool, nozzles up to 2000 gpm could be attached to thetop of a tank wall. Specifically again, on “a rim seal fire,” with thisimproved technique, a portable foam wand device was again used todispense foam downward to establish a “beachhead” area. A fire fighterthen carried a Daspit Tool™, (being a clamping device used to secure atemporary fire fighting monitor and nozzle to the top edge of a storagetank, or any other approved mounting location) and hose while climbingthe ladder and attached the Tool to the tank rim above the beachhead.The monitor and nozzle were then pressurized with water/foam solutionand directed by the fire fighter stationed at the landing to dispensefoam inside the tank and shoot out fire located around the tank'sperimeter. The entire attack could be set up and executed in a matter ofminutes, after, of course, the responding fire fighters had arrived atthe scene.

Full Surface Fire

In September of 2004 Williams was called to Cushing, Oklahoma to assistin the extinguishment of a “full surface” 117 foot diameter crude tankfire. The Williams team arrived with portable foam wands and with“Daspit Tools,” monitors and nozzles. (Again, “Daspit Tools” permitstaging a monitor and nozzle on a tank wall rim. The “Daspit Tool”provides a base for a monitor and nozzle.) Williams first used portablefoam wands to extinguish the fire around an area under a platform andladder along the wall of the tank. Having gained “control” of thatlimited area, Williams personnel mounted the ladder of the burning tankto the platform, secured a Daspit Tool there and directed its monitorand nozzle to extinguish the full surface crude tank fire. Thus,Williams provided evidence that a portable foam wand and sufficientlylarge portable monitor and nozzle (rendered useable by virtue of theDaspit Tool base) could be effectively used to extinguish a “fullsurface tank fire”, at least of crude in at least a 117 foot diametertank.

Williams Fixed Systems Development

Williams had long appreciated that a “fixed” system, performingappropriate tasks, would be faster and offer much lower risk of harm anddanger to personnel. (Danger to personnel includes the clutter on aladder provided by the hoses necessary to supply a portable monitor anda wand. Furthermore, if such hose were to break while it runs up theladder, the personnel involved with the ladder and platform would be putin significant danger.)

A problem to solve, and a goal for Williams in industrial tank firefighting, became to develop a cost-effective, reliable, fixed system forquickly and efficiently blanketing appropriate areas of a tank fire withfoam, including not only the “periphery,” (which is the location of the“rim seal fire,”) but also a tank “full surface fire.” Such system,moreover, should perform satisfactorily for tanks of 200 and 300 and 400feet diameter, and even greater, and include tanks with and/or without afixed roof, and should not be prohibitively expensive.

The resulting Williams commercial embodiments, discussed below, weredeveloped, tested and designed to solve these problems and meet thesegoals. The commercial embodiments were designed to protect: (1) floatingroof only tanks against “rim seal fire” and vapor hazard; (2) floatingroof only tanks against “rim seal fire” and full surface fire; and (3)fixed roof tanks against any surface hazard. The inventive systems arecost-effective and practical, for tank diameters from 100 feet to above400 feet.

The instant inventors have demonstrated, in the development process thatthe industry erred in certain prior assumptions regarding the properexpansion of foam needed for fixed systems, and regarding the capacityto throw or project and run an adequately expanded foam.

The instant inventors have demonstrated, with side by side testing, that“projecting” and “directionally discharging” an “aerated foam” (anexpansion of between 2-to-1 and 8-to-1) from an aerated foam nozzle canproduce a focused stream of at least 1100 gpm of aerated foam, with asignificantly enhanced tight landing footprint, and with a surprisingfoam run, and including a surprising foam run speed and firefightingeffectiveness. The inventors have shown, with testing, that theiraerated foam nozzles can reach a more extensive tank fire surface in ashorter period of time than can prior art “foam chambers.” The novelsystem can extinguish larger tanks with fewer units and is applicablenot only to rim seal fires but also to full surface liquid tank fires,including of those of large tanks. The instant inventions, supported bytest results, promise cost effective fixed systems to extinguish firesin tanks of diameters greater than 200 feet, greater than 300 feet, andgreater than 400 feet. The instant fixed systems are designed to beattached along the tank outer wall, and to discharge into the tank froma point near a top tank wall portion, thereby enhancing the reliabilityas well as the cost effectiveness of the fixed system, in the event of ahazard.

Invention Development Stages

The instant invention proceeded in several stages. A first determinationwas made, based on experience and testing, to actively pursue outer tankwall mounted units discharging proximate the tank wall upper rim. (Theinventors have experimented with “bubble-up” or so-called Type I systemsbut have not yet been able to successfully test a satisfactory,practical and cost effective bubble-up system. Pipe-inside-the-tanksystems, based on extensive experience, were deemed impractical giventhe prevalence of floating roofs and the complications inherent therein.In regard to roof mounted systems, either fixed roof or floating roof orsystems that “extend-over” the top of the liquid, experience againindicated far too high a likelihood that such a fixed system would beplaced out of service by the very incident that causes the fire orhazard.)

A second determination, based on testing, was to preferably dischargeaerated foam from an aeration chamber proximate to and upstream of thenozzle, the aerated foam preferably having at least a 2-to-1 to 8-to-1expansion ratio. A 3-to-1 to 5-to-1 ratio was preferred. A tubular jetambient air aeration chamber provided a reliable structure for theaeration, able to perform while enduring heat and stress. It wasdetermined by testing that this aerated foam could be significantlyprojected, could produce a significant foam run, and could run quicklywithout losing firefighting effectiveness.

Thirdly, the inventors created a nozzle that could significantly,directionally, “project” and/or “forcefully project” a proper aeratedfoam in a “substantially focused stream,” to land in a focused pattern,with an enhanced tight landing footprint, and again with significantfoam run and effective fire extinguishment characteristics. A key tothis stage was a stream shaper.

One general belief in the industry had been that “forcefully projecting”aerated foam destroyed the bubbles and resulted in poor foam quality andpoor foam run. Prior art fixed systems with aerated foam chambers didnot “forcefully project” aerated foam. Rather, for rim seal fires and/orsmall tanks, they poured or dropped by gravity highly aspirated foamdown the inside walls of the tank. This resulted in a low gpm ofdischarge and a poor foam run.

The instant inventors demonstrated that, with the instant nozzles, theexpectation of poor bubble quality and poor foam run for “projected” or“forcefully projected” aerated foam was misplaced. Use of a streamshaper may be instrumental in helping to secure the good results andenhanced landing footprint.

Testing has shown that a stream shaper can significantly enhance theintegrity and focus of thrown footprints of aerated foam. Aerated foamdischarged through a proper stream shaper has non-destructively landedat least dozens of feet away, in tightly focused footprints, and runsurprisingly further and quicker than industry predictions, whilemaintaining the firefighting effectiveness of the bubbles. A 2-to-1 to8-to-1 expanded foam, preferably a 3-to-1 to 5-to-1 expanded foam, canbe non-destructively landed in tight target areas to a greater extentand further away than industry expectations. The stream shaper is onekey why the instant system can land foam at least 20 feet away in a tank“periphery” and run the foam greater than 100 feet further in theperiphery. In preferred embodiments a footprint-enhancing stream shaperfor an aerated foam nozzle has four or greater fins, each fin having alongitudinal dimension greater than a radial dimension. Preferably eachfin has a longitudinal dimension greater than twice its radialdimension. Preferably also the stream shaper fins are installed in a tipof a nozzle such that the downstream end of the fins is approximatelyflush with the nozzle tip discharge orifice.

Terms

The following use of terms is helpful in discussing the structure andperformance of the instant inventions as they developed.

The term “riser” is used to refer to any pipe or line or system of such,affixed to or near or adjacent to an outer tank wall, installed toprovide water, water and foam concentrate and/or firefighting fluid to atop portion of a large industrial storage tank. Although risers areshown herein as vertical pipes, they could be any shape, and inparticular, they could be a combination of vertical and/or circularportions. E.g. one or more fluid distribution rings could be installedaround a tank, connecting with vertical riser portions. A riser can comein sections, as illustrated herein.

A “tip” of a nozzle is a nozzle barrel portion terminating in adischarge orifice, frequently including a swedge-down portion to enhancedischarge pressure.

A “fin” (also referred to in the art as a vane) directs fluid flow in aconduit.

A “stream shaper” provides fins or vanes extending in a nozzle orconduit. A fin radial dimension is the dimension measured radially froma center axis of a barrel or conduit out toward the barrel or conduitwall. A fin longitudinal dimension is the dimension of the fin measuredlongitudinally in a nozzle or conduit, along a nozzle or conduitlongitudinal axis or in the upstream/downstream direction of flow.

A “deflector,” as used herein, provides an obstruction in a fluidconduit, directing a portion of fluid flowing therein toward a dischargeorifice or port.

A tank “periphery” is an annular area on an top of a floating tank roof,between the tank wall and the floating roof “foam dam.” Foam dams areusually 24 inches high or 12 inches high. A “rim seal fire” is a fire inthe “periphery.” (A full surface fire can ensue when a floating rooffails, e.g. sinks or tilts.)

An “aerated foam nozzle” or an “aerated foam projecting nozzle” will beused to indicate a nozzle that discharges foam created from a foamingconcentrate that has passed through an ambient air aeration chamberlocated at, proximate to, and/or just prior to, a nozzle.

Two nozzles discharging “in roughly opposing directions” will be used tomean discharging in roughly opposite directions, within at least +/−150of a median “directly opposite” directional axis. By one measure, thus,the included angle between two discharge axes of two nozzles dischargingin roughly opposing directions, taken in the direction of discharge,will be between 180° and 150°.

A “substantially focused” stream indicates a discharge of foam where atleast 60% of the foam remains within a 20 degree cone around a dischargeaxis during flight.

A “projecting” nozzle means a nozzle that, if set at 0° inclination tothe horizon and at a supply pressure of 100 psi, and if a landingfootprint is measured on a horizontal plane five feet below thedischarge orifice, and when throwing aerated foam with an expansion ofbetween 3/1 and 5/1, then the nozzle can land at least 50% of theaerated foam greater than 5 feet from the discharge orifice and can landsome foam greater than 20 feet. “Projecting” thus means landing at least50% of foam, aerated with an expansion of between 3-to-1 to 5-to-1,greater than 5 feet from the nozzle discharge orifice and landingsignificant foam greater than 20 feet, if discharged horizontally andmeasured on a plane five feet below the discharge orifice.

A “forcefully projecting” nozzle means a nozzle that, if set at 0°inclination to the horizon and at a supply pressure of 100 psi, and if alanding footprint is measured on a horizontal plane five feet below thedischarge orifice, and when throwing aerated foam with an expansion ofbetween 3-to-1 and 5-to-1, then the nozzle can land at least 50% of theaerated foam greater than 50 feet from the discharge orifice and canland some foam greater than 80 feet. “Forcefully projecting” thus meanslanding at least 50% of foam, aerated with an expansion of between3-to-1 to 5-to-1, greater than 50 feet from the discharge orifice andlanding some foam greater than 80 feet, if discharged horizontally andwith a landing footprint measured on a horizontal plane 5 feet below thedischarge orifice.

The concepts of “substantially focused” stream and “projecting” and“forcefully projecting” together with “aerated foam nozzle” helpdistinguish the instant inventive nozzle and wand systems from aspiratedfoam discharge devices of the prior art. Prior art discharges fromtraditional “foam chambers” or “foam pourers” are not “substantiallyfocused” or “projecting.” On the other hand, the term “aerated foamnozzle” distinguishes the instant nozzles from master stream nozzles ofthe prior art, for instance, nozzles that throw a water/foam concentrateliquid mixture where essentially all aeration takes place significantlyafter leaving the nozzle structure rather than in an associated upstreamor in-nozzle aeration chamber.

Given the surprisingly good foam run results with the instant nozzledesign and aerated foam, the inventors tested “opposing nozzle” fixedunits, referred to by the inventors as “wand heads” and “wands.” “Twonozzle” and “three nozzle” fixed units, or “wand heads” or “wands,” weretested, discharging roughly horizontally and primarily left and/orright, and optionally, “toward the center.” For insertion throughexisting openings in a wall of a “fixed roof” tank, a conduit with asingle center pointing nozzle plus dual non-obtrusive side ports withinterior deflectors was tested, the unit suitable for inserting intoexisting fixed roof tank wall flanged openings.

The “wand heads” are adapted to be supplied by “risers,” mounted on,proximate to or about outside tank wall portions, the “wand heads” to besecured so as to discharge just inside a top tank wall portion, forenhanced reliability. The “wand heads” preferably include a proximallylocated ambient air aeration chamber providing properly aerated foam forthe nozzle(s). The aeration chambers are served by water/foamconcentrate line(s) or pipe(s), again typically referred to as “risers.”A fixed wand head with two opposing nozzles preferably directsdischarges roughly left and right, projecting aerated foam substantiallyhorizontally and in roughly opposing directions. A fixed separate riserand fitting can be provided, especially proximate a tank ladder andlanding platform, to supply and support an additional fixed nozzle orportable monitor and nozzle, which can project foam toward the center ofthe tank or otherwise around the tank. Preferably a “three nozzle” fixedunit for open floating roof tanks can be installed to discharge left,right and roughly toward the center. For fixed roof tanks, a singlecenter pointing nozzle with two conduit-located deflection ports can beinstalled, the ports functioning as side nozzles. The unit can beinserted through flanged openings typically provided in existing fixedroof tanks. The single conduit nozzle plus two “deflector ports” candischarge left, right and toward the center of a tank with a fixed roof.

(The inventors further teach, for alcohol or the like liquids, possiblynot discharging both left and right but alternately discharging all leftor all right, to establish a swirl pattern run, and to further bank thedischarge against the wall to minimize plunge.)

(Preferably in most embodiments a fourth smaller orifice will dischargea relatively small amount of aerated foam, say less than 150 gpm,directly down the tank wall to land and cover tank surface directlyunder the unit. Frequently this small fourth discharge port may not bementioned herein, and in many cases it appears unnecessary. However, itwill likely be included in commercial units out of caution.) The instantsystem thus offers a cost effective solution to a costly and dangerousproblem.

Providing first responding fire fighters with a proper means forsuccessful extinguishment of at least tank rim seal fires, andpreferably also means for full surface vapor suppression and means forextinguishing full surface liquid tank fires, by strategically andpermanently fixing a relatively few inexpensive components onto a tank,as well as providing supporting tools (monitors, nozzles, hose, andpumps), should be paramount in considering how to best protect a hazard.Doing so ensures a good relationship with the first responders as wellas provides a better solution to large tank hazards.

To recap and reflect on the development history, a Williams two stage“fully portable” attack for “rim seal fires,” and even for “full surfaceliquid tank fires,” has been successful. However, as required by the twostage “fully portable” attack, requiring humans to carry hoses up a tankladder to the tank landing, and to charge the hoses around their feet inorder to activate a primary system, presented a personnel risk that wasnot attractive. Unmanned or largely unmanned fixed systems presented afar more attractive personnel environment. However, any fixed orsemi-fixed system must also approach the degree of reliability andflexibility and cost effectiveness as that provided by the two stage“portable” system.

A surprising discovery that heightened the reliability, costeffectiveness and flexibility of the instant fixed systems, came withthe testing of a landing footprint-enhanced, “aerated” foam nozzle“projecting” aerated foam. The aerated foam nozzle, with tight landingfootprint-enhancement, tested to show that it could “throw” aerated foamsignificantly left and/or right while still landing a predominantportion of that foam in the narrow tank “periphery.” Further, the nozzlecould throw or project aerated foam successfully for a significantdistance, e.g. at least 20 feet, while landing the foam predominately inthe periphery. And the momentum of the “throwing” or the projectingenabled the system to “run” foam, tests showed, a surprising distance,120 feet both left and right of the nozzle, and to do so very quickly.As a result, a footprint-enhanced aerated foam nozzle could form asuitable cost effective primary fixed means for at least extinguishingrim seal fires. To compare with the Williams prior “portable system,”the prior portable foam wand was only used to establish a “beachhead”directly below the wand, which allowed humans to mount the tank wall atthe wand position by the ladder and to put into place the primary fireextinguishing system, fed by hoses running up the ladder. To thecontrary, with the instant novel fixed systems, a portable monitor andnozzle, if used, becomes secondary. A “fixed left and/or right wand”becomes the key element of the primary fire extinguishing system for the“rim seal fire.” A further fixed center pointing nozzle covers a fullsurface fire.

DISCUSSION OF OTHER DISCOVERED TEACHINGS

The problem of an effective practical reliable design for a fixed fireextinguishing system for tank fires, especially in tanks of diameter ofgreater than 100 feet and 200 feet, has existed for a long time. Searchinto existing solutions uncovered the following.

Foam Chambers—For example, Blomquist U.S. Pat. No. 3,876,010

For floating roof seal fires, “foam chambers” or “foam pourers,”discussed above, dropping highly aspirated foam between a tank wall anda floater roof “foam dam” have been a traditional fixed firefightingsystem solution. These systems are inadequate to attack a “full surface”fire in a >200 foot diameter tank and likely inadequate for >a 100 footdiameter tank. Their foam run is typically less than 50 feet, so that alarge number of such chambers are required. Given the degree ofexpansion imparted to the foam, the foam run is slow and short and thegpm is limited. Applicant experimented with the common foam chambers toconfirm that the run of their highly aspirated foam was only about 40-50feet in each direction around the tank perimeter or periphery (e.g. inthe area between tank wall and the “foam dam” on the floating roof) Andthis 40-50 foot run was also relatively slow.

Saval and Knowsley

A “Saval” apparatus was noticed on the Internet and a similar Knowsleyapparatus discovered. This apparatus type proposes two 450 down pointingnozzles, “discharging” left and right, stationed along the wall rim, (aswell as a small directly downward discharge). The two 45° nozzles do notdischarge “significantly horizontally” and no nozzle is proposed todischarge “toward the center” of the tank. Further Saval's nozzlesappear to “bank” their discharges against the tank wall. The effect ofbanking could be to soften the impact of landing on the liquid and/or todirect more of the foam into the periphery and/or to heighten theaeration. However, one of skill in the art knows that the “banking”technique lessens the lateral force behind the foam, wastes projectionenergy and reduces foam run capability. Neither Saval nor Knowsley claima novel or exceptional “foam run” capability. This implies that Saval'sand Knowsley's foam run is in the same order as that of the traditional“foam chambers” and/or “foam pourers.” Uribe US Patent Publication No.US 2004/0140106

Uribe teaches a tank wall mounted fixed system nozzle with an aerationchamber. The degree of aeration is not mentioned. No stream shaper isdisclosed. Uribe does not discharge right or left, but only toward thecenter, as with the Nihilator below. Uribe asserts that eventually hisdischarged foam will cover a whole tank surface. Since one of ordinaryskill in the art knows that foam has a limited lifetime and a limitedrun, Uribe's statement implies that Uribe's tank is inherently of lessdiameter than 100 feet.

Nihilator

Reference to a Nihilator device was located, although the Nihilatorappears to be no longer offered as a commercial product. One of ordinaryskill might surmise that the Nihilator was not effective. The Nihilatoris a center pointing nozzle apparently designed for a fixed roof tankand has an aeration chamber. The Nihilator discharges foam toward thecenter of the tank and suggests that it be used with traditional foamchambers.

MAJOR COMMERCIAL EMBODIMENTS

The instant invention and its related embodiments have several majorcommercial embodiments.

For ease of reference, the current major commercial embodiments aregiven graphic names.

Primary Target—Floating Roof but No Fixed Roof—Large Tanks

-   -   “Point and Shoot” (semi-fixed) System—Useful for:        -   Rim seal protection and fire fighting        -   Full surface foam blanket when no fire exists, e.g. for            sunken roof vapor suppression            -   Advantages:        -   Each wand can protect up to 240′ of seal rim circumference,            as opposed to 40′ or 80′ with conventional foam chambers;            therefore fewer wands are needed        -   Portable monitor and nozzle provides back-up redundancy and            vapor suppression capability        -   Low costs, minimal installation    -   “Ambush” (fixed) System—Useful For:        -   Full surface protection, rim seal fire and fully engaged            full surface liquid tank fire (floating roof sunk)        -   Number of systems per tank depends on tank diameter (and            product stored)        -   System can be used to extinguish rim seal rim fires with            center nozzle valved off so as not to overload a floating            roof            -   Advantages:        -   Left/right/center (and possibly down-the-wall) streams can            discharge and/or project aerated foam in 3 or 4 directions        -   System capable of discharging 1900 gpm from each assembly on            the largest model        -   Each wand can protect up to 240′ of seal rim and up to 150′            toward the center        -   Requires significantly fewer wand installations than prior            art            -   Primary Target—Fixed Roof, Large Tank    -   “Hollow Point” (fixed) System—Useful for:        -   Closed roof, full tank protection            -   Advantages:        -   Easy installation on existing tanks, through existing single            6″ flanged holes.        -   Each wand can protect up to 240′ of seal rim and up to 250′            toward the center        -   Incorporates a Teflon vapor seal to stop vapors from            traveling down the tube and out aeration holes        -   Can project 2700 gpm of foam total, via forward and            left/right and down streams        -   Requires significantly fewer wand installations than prior            art

Again, success of the above embodiments may be based in part upon thedevelopment of a stream shaper affixed in the tip of the nozzles, whichfacilitates providing a projecting and forcefully projecting foamnozzle, as well as developing a properly aerated foam for the context.

The Major Commercial Systems and Methodologies—in Greater Detail

The invention, as introduced and discussed above, relates to variousaspects and embodiments for fixed and semi-fixed systems and methods forextinguishing liquid tank fires in large industrial storage tanks. Theinvention covers tanks with and without fixed roofs and systems that arefixed or semi-fixed, and systems developed primarily for rim seal firesand for full surface liquid tank fires.

The Semi-Fixed System (for Rim Seal Fire and Vapor Protection)—Point andShoot, Summarized

The Point and Shoot fixed wand and riser system is a semi-fixed systemthat can be used immediately for “rim seal fire” protection as well asfor vapor suppression. The Point and Shoot fixed wand and riser systemis predicated upon the successful rim-seal extinguishments made byWilliams using fully portable equipment, as well as the subsequentDaspit Tool development. Given the further development of a properaeration chamber and a stream shaped nozzle combination, aerated foamnozzle units, or “wands,” fixed to the wall of the tank become acost-effective primary “rim seal fire” extinguishing means. A furtherfixed riser, for supplying firefighting fluid to a portable monitor andnozzle, can provide redundancy in case of damage to the primary systemas well as extra full surface vapor suppression capability. (And ofcourse, further independent fixed risers with fixed center pointingnozzles offer a fully fixed full surface fire protection capability.)

Thus, the semi-fixed Point and Shoot wand and riser system and methodprovides safer and quicker extinguishment for rim seal fires, as well asa back-up for component disablement or vapor suppression. This minimalfixed wand and riser system requires only strategically permanentlyaffixing a few inexpensive components directly onto a tank. As aconsequence of a proper combination of a footprint-enhanced nozzle witha properly aerated foam, the left and right nozzles of a wand can befixed 220 to 240 feet apart, (as opposed to 40 to 80 feet apart withprior art foam chamber systems.) Thus, the footprint enhanced aeratedfoam nozzle wand system can be staged as a primary fire extinguishingsystem for the “rim seal fire” while one or more risers, installedproximate a tank landing and ladder for the quick attachment of portablemonitor/nozzles, can be regarded as redundant backup rim seal fireprotection, in case of damage to the primary system, and as a capabilityto provide full surface vapor suppression if a floating roof partiallyor totally sinks. This semi-fixed system permits attacking a seal firequickly with much less risk to personnel.

The semi-fixed elementary system, called the Point and Shoot System, hasa recommended layout as follows:

Number of Foam Wands for Full Encirclement Seal Protection 240′ CoverageFrom Each - 24″ Tall Foam Dam Required at least 220′ coverage fromeach - 12″ tall foam dam Tank Diameter No. of Foam Wands Required 0′-76′ 1  77′-153′ 2 154′-229′ 3 230′-306′ 4 307′-382′ 5 383′-458′ 6Williams Fire and Hazard Control 1-800-231-4613

Note: The number of prior art “foam chambers” which would be required toprotect the above tank sizes is many multiples of the number of theinstant novel “foam wands” required, due to the extended coverage of theinstant “foam wands” (240′ vs. 80′ or 220′ vs. 80′).

The Point and Shoot semi-fixed system is particularly applicable forlarge tanks with no fixed roof for “rim seal fires” and full surfacevapor suppression. A major advantage is low cost. The Point and Shootsystem is characterized by a pair of aerated foam projecting nozzlesattached together in a fixed “wand,” structured to discharge in roughlyopposing directions and roughly horizontally. The aerated foam tank wandhas been demonstrated to be able to land and run foam approximately 120feet in each direction in the tank “periphery,” that is the spacebetween the “foam dam” and the tank wall of a floating roof. See belowtest results. Preferably in addition to the fixed foam wands risersattached to or about the tank wall, at least one additional at leastfour inch riser is attached to the tank wall to be associated with thetank landing ladder system. The additional riser is structured tocommunicate firefighting fluid from approximately the ground toapproximately the top of the tank and is structured with a fitting atits end, proximate the top of the tank, the fitting suitable forattaching a portable (at least 150 gpm at 100 psi) monitor and nozzle.

The Fixed System for Floating, not Fixed, Roof—Including Full SurfaceFire—Ambush Summarized One new primary danger arises from the fact thatindustrial storage tanks for storing flammable liquids and hydrocarbonproducts are being constructed of ever greater diameters. Today 405′diameter tanks, and greater, are being constructed. Large scale portablefirefighting nozzles, such as 10,000 gpm, 12,000 gpm or 14,000 gpmnozzles, capable of throwing fire extinguishing and hazard suppressingliquids (water and foam concentrate) over the top of the tank walltypically recite maximum ranges in the 400-500 foot range. Firefightingfoams from the large scale portable nozzles can be relied on to run, atbest, approximately 100′. (Conservatively, the foam might only bereliably counted upon to run about 80 feet.) Thus, portable firefightingnozzles effectively addressing a full surface, fully engaged flammableliquid tank fire in a 405′ diameter tank by throwing foam over the wallfrom an upwind location probably have to be staged within 100′ of a tankwall. Considerations of logistics as well as the existence of moats,buildings and other equipment and piping around the tanks, andespecially considerations of heat and personnel safety, render extremelyproblematical any tactic requiring approaching a fully engaged fullsurface liquid tank fire in a 405′ diameter tank closer than 100′.

Further pressure for improvement comes from the fact that the value, tothe tank owner, of a gallon of the product in the tank is alsoincreasing dramatically. Owners of large tanks and of large tankproducts want the product and the tank to be protected from fire.

The above considerations incentivized the inventors to develop a fullyfixed system, including one or more fixed center pointing nozzles plusan aerated foam wand, preferably a left and right discharging wand butpossibly an all left or all right discharging wand. The system is knownas the Ambush and provides a first defense for addressing fire and vaporhazards, including full surface liquid tank fires, in all tanks withouta fixed roof, but especially in large diameter tanks.

The Ambush could be implemented in one fashion as a “fixed” Point andShoot System. The Point and Shoot riser provided with a fitting forattaching a portable monitor and nozzle, located near the tank ladderand landing, could be provided instead with a permanently fixed centerpointing nozzle, such as a master stream self-educting nozzle. The riserand nozzle could look and function much like the Hollow Point riser andnozzle, without however the lateral space constraints, the side portsand without the necessity of an aeration chamber. The adjustment of thenozzle could be fixed or set with respect to the tank size and otherfixed wands such that the nozzle covers a relevant center portion of thetank surface with foam. No separate ambient air aeration chamber wouldbe required, as known in the master stream firefighting nozzle field. Aseparate fixed riser and nozzle need not be limited to being locatednear a tank ladder and landing. Only so many fixed center directed riserand nozzles need be included as will adequately cover the center portionof the tank surface with foam, in context.

An Ambush System provides a tailored design of three nozzle units, orwands, preferably with all nozzles using one or two proximate ambientair aeration chambers and all working off of one or two associatedrisers. These three nozzle units are designed to be installed as unitsaround a tank.

The three nozzle, fixed, aerated foam wand system includes a set offixed aerated foam nozzles. This set of nozzles, each referred to as afixed “wand,” has left and/or right and over the top (toward the center)capability, all with enhanced landing footprints. Preferably the unitsof three nozzle wands are spaced around, and proximate to, the innertank wall, each unit preferably providing two nozzles that dischargepredominantly left and right, along inner tank wall portions, and athird nozzle that discharges toward the center. Preferably the “towardthe center” nozzle discharges at least beyond an approximate 80′ annularring of foam, anticipated to be created upon an open tank surface by theleft and right discharging nozzles. (In some cases the three nozzle wandunit also provides a fourth small port or nozzle to discharge directlybeneath the wand and on the inside of the tank wall.) Any disablement ofa fixed wand due to a particular fire or hazard or incident can besupplemented by large portable nozzles staged on the ground, throwingfoam over the tank wall, as is known in the art.

The perimeter of a 405′ tank runs approximately 1,250 feet. Testingshows that the instant novel fixed foam wands (Ambush System) should beable to direct foam to run at least 80′ to 90′ in each direction,preferably 120 feet, and to also run the foam 80′ or so inward towardthe center of the tank. (Again, in addition, a small amount of foam maybe discharged directly below the fixed foam wands.) These nozzles couldcover the inner tank wall with a roughly 80′ wide annular foam ring,relatively quickly. A third nozzle attached to each fixed wand,preferably with its own aeration chamber, projects foam toward thecenter of the tank and at least toward the inside of the 80′ annularfoam ring being established. Preferably, for a large tank, the thirdnozzle lands a footprint of foam with a footprint midpoint approximately90 to 120 feet radially inward of the tank wall. The length of thelanding footprint should preferably extend at least 20 to 30 feetforward and backward from the landing midpoint, along the dischargeprojection line. The landing footprint should preferably spread at least15 to 20 feet laterally from the discharge projection line. Such adischarge of foam has been shown to be capable of running foam towardand through the center of a 405′ diameter tank. Taking the centerprojected foam together with the peripherally discharged foam, a totalgpm of foam should be selected such that the surface of the tank wouldbe covered with an adequately deep and lasting foam blanket. That is,the gpm of the wands and nozzles should take into account the desiredand/or required application rate density for the tank surface.

This fixed three nozzle open system and methodology has an advantage ofconcentrating a foam blanket on portions of the tank liquid surfaceadjacent to the tank walls. The portions adjacent to the tank walls areimportant because the tank wall itself can retain significant heat. Thetank wall typically needs the most cooling. For a 405 foot diametertank, for instance, seven or eight large three nozzle fixed foam wandsmight be utilized, each large three nozzle foam wand dischargingapproximately 2,000 gpm of water/foam concentrate total from its nozzlecluster. In a preferred embodiment a nozzle discharging to the left andto the right might discharge approximately 700 gpm each. A nozzledirected toward the center might project approximately 500-900 gpmtoward the center. A small port discharging immediately under the fixedwand might discharge approximately 100 gpm downward.

Again, to the extent that one or more fixed foam three nozzle wands aredisabled by the fire or an explosion, large portable firefightingnozzles can be staged on the ground and used to supplement thenon-disabled portions of the fixed system.

In the three nozzle fixed aerated foam wand system the dischargeorifices for the nozzles preferably contain fins, or stream shapers, tominimize the turbulence in the discharge of aerated foam out of thenozzles. Minimizing turbulence enhances the range and the run of thefoam, and tightens the landing footprint.

One preferred three nozzle fixed aerated foam wand embodiment includestwo aeration chambers. The aeration chamber(s) typically consist oftubular jets inserted inside of piping proximate a series of air intakeports, and the chamber is situated proximately upstream of the nozzledischarges. The jets, in a known manner, create a low pressure zone,sucking air in through the ports and mixing the water/foam concentratewith air to create an aerated foam for discharge. Bends incorporated inthe conduit between an aeration chamber and a discharging nozzle mayenhance the aeration of the foam. No bend may be included between anaeration chamber and a center projecting nozzle, however, to minimallyaerate that foam in order to enhance foam throw and run. Discharge fromthat nozzle has a longer flight time in which to further aerate. Twoaeration chambers enable tailoring the aeration more closely to thenozzle purpose.

Although the three nozzle system was initially designed to address theproblem of a very large, fully engaged, full surface liquid tank fire(no fixed roof), such as a fire in an industrial tank having a diameterof 405 feet, the fixed three nozzles aerated foam wand system wasquickly seen to have application to tanks of all diameter sizes, and inthe situation of either a fully engaged fire or a rim seal fire orsimply a need for vapor suppression. The large fixed wand is useful evenif a floater remains in place and there is only a seal fire or a needfor vapor suppression over the floater. A valve can be provided toeliminate foam discharged toward the center in the case of a rim sealfire.

Fixed Roof Fixed Nozzle System—Hollow Point Summarized

A fixed roof fixed nozzle wand system has been designed as a directresponse to the issues faced by foam chambers when installed on a closedroof tank for the purpose of full surface protection. One wand of theinstant fixed roof fixed nozzle system projects foam directly toward thecenter of the tank as well as left and right to protect near the innertank walls. The wand unit preferably incorporates a Teflon vapor seal toprevent tank vapors from escaping the tank via the aeration holes in thewand system's supply piping.

In contrast with foam chambers that simply pour foam onto the surfacefrom the circumference of a tank, such that the foam must run across theliquid surface using only gravity as its means of propulsion via thestatic head from the piled up foam near the tank wall, the instant fixedroof aerated foam wand discharge head projects foam out into the tankwith significant velocity, to push the foam toward the center of thetank. From the same wand foam from interior left/right discharge portsis projected to protect the area near the tank walls.

As foam accumulates in the center, it will begin to flow outwards backtoward the tank walls. The foam at the tank walls will meet and flowtoward the center of the tank, closing the gap between the two.

Each fixed roof wand discharge head is preferably designed to flow 1000gpm; 600 gpm is delivered through the center stream projecting towardthe center of the tank with 200 gpm projecting left and right againstthe tank wall. This flow rate can be regulated by an internal jet justupstream of the aeration holes. Air is introduced to the stream at theaeration holes by the Venturi effect created by the internal jet. Thisaerates the foam before it leaves the wand to allow for aerated foam toland on the liquid surface. The ambient air aeration chamber ispreferably intended to create a relatively low expansion foam comparedto other devices, in order to maintain small bubble foam. This foam isbest suited for quickly and effectively running across a liquid surface,thus providing a quick coverage and extinguishment of the tank. One mainobjective of the fixed roof wand system is to improve upon currentmethods of closed roof storage tank protection. The fixed roof wandsystem does so by projecting foam, rather than pouring foam, and bycarefully engineered discharge tip sizes and designs coupled with anefficient ambient air aerator and favorable flow rates, stream shapersand stream straighteners.

One fixed roof wand system recommended layout, for example, is asfollow:

Number of Hollow Point Systems Required for Full Surface Protection 1000gpm Discharge from Each System Tank Diameter Discharge Heads Required 0′-103′  1 104′-146′  2 147′-178′  3 179′-206′  4 207′-221′  5222′-242′  6 242′-262′  7 263′-280′  8 281′-297′  9 298′-313′ 10314′-316′ 11 317′-330′ 12 Williams Fire and Hazard Control1-800-231-4613 Note: The application densities used in the abovecalculations are based upon an escalating scale from .12gpm/ft{circumflex over ( )}2 to .14 gpm/ft{circumflex over ( )}2. Thesenumbers are based upon Williams experience with extinguishing large fullsurface storage tank fires.Special Methodology—Alcohols

Alcohols and related liquids and polar solvents are known to attractwater out of foam bubbles. Foam, therefore, is preferably landed“lightly” on alcohols or like fluids to minimize the depth of any plungeof the foam below the liquid surface. The inventors teach that a swirlpattern may be preferable for running foam landing on alcohol or thelike liquids in the case of fire. Thus the inventors teach, for tanks ofalcohol or related liquids or polar solvents, a method of bankingdischarged foam against inner tank walls prior to landing the foam onthe liquid, and discharging the foam predominantly all left or allright, from a plurality of nozzles, to develop a swirl pattern run forthe foam in the tank.

Aerated Foam

The preferred foam for producing the requisite aerated foam for theinstant fixed systems is to use an ambient air aeration chamber locatedjust upstream of the nozzles. It is known in the art to produce anaeration chamber just downstream of the nozzle discharge orifice gap. Inthis sense the word nozzle is used to reference the portion of thebarrel that contains the gap, or the swedging down to the narrowestorifice, thereby recovering the greatest head pressure for discharge.Such nozzle discharge orifice gap can discharge into an aeration chamberwhere aerated foam is produced and is then discharged from the aerationchamber into the atmosphere. U.S. Pat. No. 5,848,752 to Kolacz, inparticular FIG. 3, illustrates this type of foam aeration nozzle. Also,U.S. Pat. No. 4,944,460 to Steingass illustrates this type of aerationfoam nozzle. All things being equal, a separate aeration chamberupstream of the nozzle gap is preferred. However, one of skill in theart would recognize that such is not the only way to create aeratedfoam.

Summary of Major Commercial Embodiments

The Point and Shoot system, at a minimum, includes installing a one ortwo nozzle aerated foam wand system, as a fixed system, preferably every100′ to 240′ around the perimeter of a tank, which should be sufficientto extinguish tank “rim seal fires.”

A good reason for also installing at least one fixed riser proximate alanding, for releasably affixing a portable monitor and nozzle, togetherwith the above one or two nozzle system, would be to provide redundancyand backup foam protection, in case some fixed system units were damageddue to an explosion, and to provide as well a full surface foam“blanket” for “vapor suppression” should a floating roof of the tanksink. Such a fixed monitor riser would have a fire department connectionat the bottom of the tank and a monitor quick disconnect fitting at thetop. During an event, if needed, a firefighter could carry a lightweightaluminum monitor and nozzle to the top of a tank and install the monitoron the riser pipe using the quick disconnect fitting (approximately 2minute installation). From this vantage point, the fire fighter coulddirectly apply foam to needed areas. This maximizes the effectiveness ofthe resources available to the firefighter. The danger and hazard fromlaying fire hoses up a ladder on the side of the tank to implement aportable system are avoided. Williams recommends installing a fixedmonitor riser pipe at locations near landings of the tank. This fixedmonitor riser pipe could also be used to apply foam if necessary to anyexposed areas due to a “cocked” roof or in the event a foam wand headhas been compromised due to an explosion. This elementary semi-fixedsystem minimizes initial capital investment for protection of a tankwithout a fixed roof, at least from a rim seal fire and a sunken roof,while providing a proven system that is easy to operate and to maintain.The equipment eliminates the need to drag multiple hoses up a tank'sladder which impedes firefighters from getting onto or off of the tankquickly.

The Ambush system is a fixed system particularly applicable for fullsurface liquid tank fires and/or rim seal fires, including in largetanks, again as above, preferably for tanks without a fixed roof. TheAmbush system preferably includes three nozzle aerated foam wands, withtwo nozzles that discharge in roughly opposing directions and that canbe oriented with respect to a tank to discharge roughly horizontally.The third nozzle projects in a direction roughly perpendicular to thedischarge axis defined by the first two nozzles. When oriented withrespect to the tank, the third nozzle projects roughly toward the centerof the tank with an appropriate angle of inclination. The third nozzleis preferably structured to land aerated foam at least 100 feet distant.All three nozzles significantly directionally project aerated foam.

The Hollow Point system is a fixed system particularly applicable tohazards and fire in large tanks with a fixed roof, and preferably can beinstalled in and through existing upper tank wall openings. The HollowPoint system is characterized by a conduit ending in a nozzle tip, theconduit having two side discharge ports with associated, largelyinterior “deflectors.” The ports, conduit and nozzle are structured topass through existing tank wall openings and to be oriented with theports discharging in roughly opposing directions, roughly horizontally,and the nozzle tip discharging roughly toward the center. Both thenozzle and ports preferably discharge a substantially focused stream.

The heightened projection capability and foam run capability of eachsystem described above results in the installation and servicing ofsignificantly fewer units per tank than with previous fixed systems. Thenew systems can protect significantly larger tanks with less fixedequipment and in less time. A stream shaper installed in the tip of thenozzles contributes to the heightened projection capability of thenozzles, and together with the development of a properly aerated foam,produces a focused stream and optimized foam run.

Testing

As discussed above, the current accepted fixed system for protectingstorage tanks comprises “foam chambers” (sometimes called “foampourers.”) Fixed foam chambers have limitations, one main limitationbeing their method of applying foam to a seal area. Either because of(1) the degree of aeration produced by the foam chamber and/or (2) aperceived delicacy of the foam bubble and/or the (3) dispersed footprintdischarged, the chamber is structured to only gently “pour” a greatlyexpanded foam down onto a tank's seal. The foam chamber pours; it doesnot throw or project. The foam chamber relies on gravity and the headcreated by the pile of foam to push the foam left and right of the foamchamber. This system severely limits the distance the foam can “run,”left and right of the foam chamber in the seal rim periphery area. Thissystem requires a tank to have a large number of foam chambers spacedaround the circumference, every 40 or 80 feet, depending upon whetherthe “foam dams” of the floating roof are 12″ or 24″. Many tanks are nowgreater than 300 foot diameter. Some are greater than 400 foot diameter.A 400 foot diameter tank with a 12″ foam dam would require about 23traditional foam chambers to protect the periphery. The instantinvention requires only about 6 units to protect the same periphery.

In contrast with the currently accepted fixed systems, Williams hasdeveloped an improved aerated foam nozzle system to discharge a proveneffective foam surprisingly farther, many times farther, in both leftand right directions, than traditional foam chambers. Tests show, below,that the instant system covers a larger area in less time with foam thateffectively extinguishes fire. Further, a rim mounted nozzle has beenalso demonstrated that can run foam to the center of a 400 foot diametertank.

In December of 2010 a “proof of concept” test was run at the WilliamsFire and Hazard Control test facilities. The purpose of the test was tocompare and contrast, by observation, two foam application devicesflowing into a simulated tank “rim seal periphery area,” the onesbetween a tank wall and a floating roof “foam dam.”

The purpose of the test was to determine whether the relative foam flowperformance of the novel Williams projecting foam wand could provide theanticipated benefits compared to a conventional “foam chamber.” Foamfrom both devices was discharged into a simulated floating roof“periphery,” the ones between a tank wall and a floating roof foam dam.For each device the foam traveled through this simulated wall/foam dam“periphery” to reach and extinguish a liquid hydrocarbon pan fire, whichwas simulating a storage tank floating roof “rim seal fire.” Flow ratesand distances were recorded as elements of performance along with thedelivered foam quality, foam expansion ratio and drain time.

The concept being tested was whether the foam applied through a highflow rate projecting foam wand would cover the distance in the seal areamore rapidly and protect a larger segment of a floating roof seal alongthe periphery.

The observed test confirmed the concept. Foam from the projecting foamwand traveled 3 times the distance (120 feet versus 20 feet) in 25% lesstime (74 seconds versus 101 seconds from the chamber.) Both successfullyextinguished a pan fire at their terminus. The novel foam wand appliedfoam more rapidly on the target area than the conventional foam chamber.In addition, the novel foam wand provided a gpm per square footapplication rate 50% greater (0.6 versus 0.4 US gpm per square foot)than the foam chamber. Simulated periphery dimensions were 2 four incheswide and 2 four inches deep.

To summarize the test and the results, a novel aerated foam nozzle wasset up on a mock seal area with a foam dam and flowed alongside atraditional foam chamber. The NFPA recognized maximum distance for atraditional foam chamber to cover is 80′ total, 40′ to the left andright, for a 24″ foam dam. The traditional foam chamber was able tocover this distance in 1 minute 40 seconds. The novel aerated foamnozzle was able to cover an area three times greater in significantlyless time. The aerated foam nozzle covered an area of 240′ (120′ to theleft and right) in 1 minute 14 seconds. It was shown that foam appliedthrough the novel high flow rate wand projecting left and right wouldcover a foam dam seal area more rapidly, travel further per device, andprotect a larger segment of floating roof seal along the periphery.

Further testing of a fixed Hollow Point wand, discussed above, showedthat a roughly 80′×170′ pond of water (13,600 square feet) could becovered in foam with a Hollow Point wand in approximately 1 minute and25 seconds. The furthest corner of the tank from the nozzle was 145′away. That furthest corner received ample foam coverage. The speed, runand authority of the foam was surprising.

Testing of the center nozzle of the Ambush wand, discussed above, alsoindicated a capacity to achieve an approximately 150′ end range of acenter nozzle landing footprint with the mid-point of the landingfootprint at about 130′.

In August 2011 a full Ambush system was tested on a 277 foot diameterempty tank. Six three nozzle wand units were spaced around the peripheryof the tank. The total flow per device was 1500 gpm giving a totalsystem flow of 9,000 GPM. The measured footprint size of the centerpointing nozzle was approximately 60 feet long by 20 feet wide with amid-point range of approximately 90′ away from the nozzle. Byobservation, the total surface of the tank floor was covered with foam.Photographs show testers wading knee deep in foam toward the middle ofthe tank.

SUMMARY OF THE INVENTION

The invention includes a nozzle for projecting firefighting foam in asubstantially focused stream particularly for use with fixed orsemi-fixed systems. The invention preferably includes a nozzlestructured for projecting at least 100 gpm (at 100 psi) of aerated foam,the nozzle having a tip portion defining a longitudinal axis andterminating, in contain preferred embodiments, in a solid bore dischargeorifice. The tip portion has a stream shaper. The stream shaper caninclude at least four fins with a longitudinal dimension in the tipportion greater than a radial dimension in the tip portion and with thefins terminating substantially flush with a nozzle tip solid boredischarge orifice.

The invention also includes a nozzle for projecting firefighting foam ina substantially focused stream including a nozzle structured forprojecting at least 100 gpm (at 100 psi) aerated foam, the nozzle havinga tip portion defining a longitudinal axis and terminating in adischarge orifice that is not necessarily a solid bore. This tip portionpreferably has a stream shaper having greater than four fins, the fourfins having a longitudinal dimension in the tip portion greater thantwice a radial dimension in the tip portion, with the fins terminatingsubstantially flush with the nozzle tip discharge orifice.

Preferably a focused stream, aerated foam projecting nozzle isproximately attached downstream of, and in fluid communication with, anambient air aeration chamber. Preferably an ambient air aerationchamber, in combination with a nozzle, is structured to project foamwith an expansion of between 2-to-1 to 8-to-1, and more preferably, withan expansion of between 3-to-1 to 5-to-1.

Preferably at least one aerated foam projecting nozzle is attachedproximate the top of an at least a 100 foot diameter industrial tankwall and placed in fluid communication with a riser attached to, orproximate to, the at least 100 foot diameter industrial tank wall.

The invention preferably includes a wand having at least one aeratedfoam projecting nozzle for projecting foam in a substantially focusedstream and in a roughly horizontal direction around an inside tank wallsurface. The invention can include a first ambient air aeration chamberlocated upstream of, proximate to and in fluid communication with atleast one aerated foam projecting nozzle, the aerated foam projectingnozzle having at least four fins and a tip portion, the fins having alongitudinal dimension greater than a radial dimension and terminatingsubstantially flush with a nozzle tip discharge orifice. The aerationchamber is preferably structured together with a nozzle to project atleast 100 gpm of aerated foam (at 100 psi) having an expansion ofbetween 2-to-1 to 8-to-1. The nozzle and chamber are preferably attachedto a riser for communicating water and foam concentrate and the at leastone nozzle and riser are preferably structured in combination forattachment to a tank wall of at least 100 feet diameter such that thenozzle projects foam in a roughly horizontal direction around aninterior top tank wall surface.

The invention can include a wand having at least one aerated foamprojecting nozzle for projecting foam in a substantially focused streamin a roughly horizontal direction around an inside tank wall surface anda first ambient air aeration chamber, located upstream of, proximate toand in fluid communication with the at least one aerated foam projectingnozzle, the nozzle structured for projecting aerated foam in asubstantially focused stream. The chamber is preferably structuredtogether with a nozzle to project at least 100 gpm of aerated foamhaving an expansion of at least 2-to-1 to 8-to-1. The nozzle and chamberare preferably attached to a riser for communicating water and foamconcentrate and the at least one nozzle and riser are preferablystructured in combination for attachment to a tank wall of an at least a100 foot diameter tank such that the nozzle projects foam in a roughlyhorizontal direction around an interior top tank wall surface.

Preferably the invention includes two aerated foam projecting nozzles,the two nozzles structured in combination to project in roughly opposingdirections. Preferably the aeration chamber and nozzles are structuredtogether to project aerated foam with an expansion of between 3-to-1 to5-to-1.

Preferably a wand system includes an at least two inch riser structuredto extend from proximate a ground location to a wand head locatedproximate an at least 45 foot high industrial tank top wall portion, andthe system includes a plurality of such wands attached around the tankwall at at least 150 feet apart, or at at least 200 feet apart or at atleast 220 feet apart or at least 240 feet apart.

Preferably included with a wand system is an at least four inch riserlocated proximate the tank wall having either a fitting for attaching aportable monitor and nozzle or having attached a fixed nozzle. Aportable monitor and nozzle and/or fixed nozzle can provide a centerpointing nozzle for discharging aerated foam toward the center of thetank.

The invention preferably includes a method for projecting asubstantially focused stream of aerated foam that includes supplyingwater and foam concentrate to an ambient air aeration chamberproximately attached upstream of, and in fluid communication with, afire fighting nozzle. The invention can include projecting aerated foamwith an expansion of between 2-to-1 to 8-to-1 from the nozzle in asubstantially focused stream, the nozzle having a tip with at least fourfins, the fins having a longitudinal dimension greater than a radialdimension, and the fins terminating substantially flush with a nozzletip solid bore discharge orifice.

The invention also preferably includes a method for projecting asubstantially focused stream of aerated firefighting foam that includessupplying water and foam concentrate to an ambient air aeration chamberproximally attached upstream of, and in fluid communication with, a firefighting nozzle and projecting aerated foam with an expansion of between2-to-1 to 8-to-1 from the nozzle in a substantially focused stream. Thenozzle preferably has a tip with greater than four fins, the fins havinga longitudinal dimension greater than twice a radial dimension andterminating substantially flush with a nozzle tip discharge orifice,which is not necessarily a solid bore.

The method preferably includes projecting foam with an expansion of3-to-1 to 5-to-1 and projecting foam into an at least 100 foot diameterindustrial tank from a position proximate a top tank wall portion, andwherein the nozzle is attached to a riser proximate the tank wall.

The invention can include a method of providing fixed wands around atank wall for projecting foam against interior tank wall portions aswell as providing risers and one or more center pointing nozzles forprojecting foam toward the center of the tank.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when thefollowing detailed description of the preferred embodiments areconsidered in conjunction with the following drawings, in which:

FIG. 1A illustrates three “wand head” embodiments with nozzles forprojecting firefighting foam in a substantially focused stream andaeration chambers.

FIG. 1B illustrates a prior art foam chamber, for contrast.

FIG. 1C illustrates an alternate embodiment for a fire fighting nozzlewherein the discharge orifice comprises an annular discharge orifice (nostream shaper shown.) FIG. 2 illustrates an embodiment of a 3 inch foamwand head having two nozzles for projecting fire fighting foam inroughly opposing directions, together with associated riser portions.

FIG. 3 illustrates a further embodiment of a wand with a wand headattached to a riser, the wand head and riser being attached to a tankwall.

FIG. 4 illustrates in a cross section the wand head of FIG. 3.

FIG. 5 illustrates, with cross section, a further embodiment for a wandhead with center pointing nozzle for projecting firefighting foamincluding a riser portion and an ambient air aeration chamber.

FIG. 6 illustrates the embodiment of FIG. 5 attached to a tank wallportion and retrofitted to an existing tank with a fixed roof.

FIGS. 7A-7F are drawing sheets for the embodiment of FIG. 2, giving ageneral overview for a foam wand together with detailed drawings ofvarious parts of a foam wand system.

FIGS. 8A-8M provide drawing sheets for a wand head as in FIG. 2 and FIG.7, with various parts identified, including nozzle parts and a streamshaper and an ambient air aeration chamber.

FIG. 9 illustrates portions of a free standing riser to be attachedproximate to an industrial tank wall and suitable for servicing a nozzleor nozzle and monitor. In this embodiment the riser is broken into a topriser top portion, a riser extension pipe and a riser inlet pipe.

FIG. 10 illustrates a riser foot rest for a lower end of a riser.

FIGS. 11A-11G provide drawing sheet depictions for the monitor riserembodiment of FIGS. 9 and 10.

FIG. 12 illustrates an embodiment of a free standing riser for attachinga portable monitor and nozzle and with a portable monitor and nozzleattached.

FIGS. 13A and 13B provide drawing sheets for a point and shoot systemincluding a wand and a free standing riser with a portable monitor andnozzle attached.

FIGS. 14 and 15 give a side view and a view from inside the tank of thepoint and shoot system of FIGS. 13A and 13B, including the wand with apair of aerated foam nozzles discharging in roughly opposing directionsand an independent riser having a portable monitor and nozzle attached.

FIG. 16 illustrates a designed deployment of the point and shoot systemfor a 300 foot storage tank for rim seal and vapor protection. Foam wandlocations are indicated and one riser is indicated at the landing forplacement of a portable monitor and nozzle.

FIGS. 17, 18 and 19 relate to the deployment of the point and shootsystem.

FIG. 17 illustrates the ladder around a typical tank leading up to atank landing.

FIGS. 18 and 19 provide an estimate of the number of foam wand locationneeded for full encirclement seal protection assuming a 24 inch foam damon the floating roof or a less than a 24 inch foam dam on the floatingroof.

The drawings are primarily illustrative. It would be understood thatstructure may have been simplified and details omitted in order toconvey certain aspects of the invention. Scale may be sacrificed toclarity.

DETAILED DESCRIPTION

FIG. 1A illustrates three embodiments of a wand head WH with one or morenozzles NZ for projecting firefighting foam in a substantially focusedstream. Each nozzle NZ has a tip portion TP defining a longitudinalaxis. The embodiments of FIG. 1A all terminate in a solid bore dischargeorifice. The tip portion TP of each nozzle NZ has a stream shaper SScomprised of fins FN.

As is common in the industry each nozzle includes a swedge-down area SWfor recovering head pressure in order to enhance the range of thedischarge.

The nozzle of these preferred embodiments utilize a solid bore dischargeorifice DO. However, it is anticipated that roughly equivalent nozzlescan be constructed using an annular bore discharge nozzle. An annularbore discharge nozzle is illustrated in principle in FIG. 1C. An annularbore discharge nozzle is created by a deflector or bafflehead BH placedin a fluid flow conduit. The deflector or bafflehead creates theswedge-down effect for the recapture of head pressure for discharge, andthe nozzle “gap.”

The three wand head embodiments of FIG. 1A illustrate one or morenozzles NZ, typically connected to a conduit CD, and thence to anupstream ambient air aeration chamber AAAC. A support plate SP isillustrated as one means of helping to affix the foam projecting nozzlesto a top portion of an industrial tank wall at a desired height.

FIG. 1A also briefly illustrates connection of a wand head WH with oneor more nozzles to a riser portion RS. The riser RS is simply a pipe ora line or the like used to bring water and foam concentrate up the tankwall to the wand head and the nozzles.

FIG. 1B illustrates a prior art foaming chamber FC with a typical“pouring” foaming chamber discharge orifice FCDO.

As discussed above, FIG. 1C illustrates a wand head with projectingnozzles having not a solid bore discharge orifice but an annulardischarge orifice, created by a deflector baffle head BH.

FIG. 2 illustrates in greater detail a three inch wand head WHcomprising a combination of a pair of nozzles NZ, each with a tipportion TP, each tip having a stream shaper SS. The pair of nozzles areconnected by conduit CD to an ambient air aeration chamber AAAC. Also inthe drawing is a riser pipe RS (in two sections) that can be connectedto the lower portion of the wand head. An inlet pipe RSL is illustratedthat can be connected to an upper portion of the riser pipe and providea connection to water and foam concentrate hose or piping.

FIGS. 3 and 4 illustrate in full as well as in cut-away a furtherembodiment incorporating three of the instant aerating foam projectingnozzles into a wand head WH. Each nozzle NZ has a tip TP and a streamshaper SS. Upstream of the nozzles are first and second ambient airaeration chambers AAAC. A support plate SP helps to assist affixing thenozzles NZ to the top of a tank wall TW in desired locations, as shownin FIG. 4. A partial section of a riser RS below the wand head is shownin FIG. 4, including brackets BR in FIG. 3 useful for affixing orstabilizing the riser RS with respect to the tank wall TW. Wind girderWG is also illustrated in FIG. 3.

FIG. 5 illustrates a cut away of a different version of a nozzle NZhaving tip portion TP with stream shaper SS. Conduit CD is shownconnecting nozzle NZ with ambient air aeration chamber AAAC havingtubular jet TJ. A portion of riser RS is also illustrated in FIG. 5.

FIG. 6 illustrates the embodiment of FIG. 5 with riser RS attached totank wall TW using brackets BR. Nozzle NZ is inserted through an openingTWO in the tank wall TW. The tank is shown with a tank fixed roof TFR.

FIGS. 7A-7F provide drawings for an embodiment of a foam wand in generaloverview. The wand head WH is shown resting on a wand support plate SP.Foam wand riser RS is shown affixed to a wand head portion. Foam wandmounting clamps or brackets BR are illustrated for mounting riser RS tothe side of a tank wall TW. The assembly of the foam wand riser pipe andwand head together with foam wand support plate is illustrated in FIG.7F.

FIG. 8 illustrates a foam wand head WH in greater detail including inparticular an embodiment of a stream shaper SS comprised of fins FN thatfits in a tip portion TP of the nozzles on the foam wand head WH. FIG.8B illustrates a crosswire screen CW placed in the ambient air aerationchamber just downstream of the tubular jet TJ, with one eighth inchcross wires to break the jet stream at that portion of flow.

The foregoing figures illustrate various embodiments of an aerated foamprojecting nozzle to project firefighting foam in a substantiallyfocused stream, and in particular a nozzle structured for projecting atleast 100 gpm of aerated foam at 100 psi. As can be seen the nozzle hasa tip portion defining a longitudinal axis and preferably terminating ina solid bore discharge orifice. However, an annular discharge orificeshould also work. The tip portion of the nozzle incorporates a streamshaper and, as frequently included, a swedge-down portion. The streamshaper has at least four fins with a longitudinal dimension in the tipportion greater than the radial dimension in the tip portion. It can beseen that the fins terminate substantially flush with the nozzle tipdischarge orifice in the preferred embodiments. FIG. 8E illustrates thatpreferably greater than four fins are employed and preferably the finshave a longitudinal dimension LD greater than twice the radial dimensionRD (See FIGS. 8E, 8H, 8L). Also preferably, the nozzle is structured toflow between 100 gpm and 900 gpm at 100 psi.

As further illustrated by the foregoing figures, a nozzle for projectingaerated firefighting foam in a substantially focused stream isproximately attached downstream of, and in fluid communication with, anambient air aeration chamber, AAAC. The ambient air aeration chamberpreferably includes a tubular jet structure TJ, preferably also withcrosshairs CW or a cross haired screen just downstream of the tubularjet structure TJ to further break up the flow. (See FIG. 8B.)

Preferably the nozzle and ambient air aeration chamber are structured incombination to project foam with an expansion of between 2-to-1 to8-to-1. More preferably, the nozzle and aeration chamber are structuredin combination to project foam with an expansion of between 3-to-1 to5-to-1.

The nozzles for projecting firefighting foam in a substantially focusedstream are particularly adapted for being attached proximate a topportion of an at least 100 foot diameter industrial tank wall, asillustrated in FIGS. 3 and 7F. A riser RS preferably places the nozzlefor projecting aerated firefighting foam in a substantially focusedstream proximate a top portion of an industrial tank wall and providesthe nozzle and aeration chamber with a source of firefighting water andfoam concentrate.

In operation a substantially focused stream of aerated firefighting foamis projected by supplying water and foam concentrate to an ambient airaeration chamber proximately attached upstream of, and in fluidcommunication with, an aerated foam projecting firefighting nozzle, andby projecting aerated foam with an expansion of between 2-to-1 to 8-to-1from the nozzle in a in a substantially focused stream, the nozzlehaving a tip of at least four fins, the fins having longitudinaldimension greater than a radial dimension and terminating substantiallyflush with a nozzle tip solid bore discharge orifice DO. (See FIG. 8A.)

In operation also, a substantially focused stream of aeratedfirefighting foam can be projected by supplying water and foamconcentrate to an ambient air aeration chamber proximately attachedupstream of and in fluid communication with an aerated foam projectingfoam firefighting nozzle. The method includes projecting aerating foamwith an expansion of between 2-to-1 to 8-to-1 from the nozzle in asubstantially focused stream with the nozzle having a tip of greaterthan four fins and the fins having a longitudinal dimension greater thantwice the radial dimension, the fins terminating substantially flushwith a nozzle tip discharge orifice.

Preferably the methodology includes projecting foam with an expansion ofbetween 3-to-1 to 5-to-1 into an least 100 foot diameter industrial tankfrom a position proximate a top portion of a tank wall.

Again, FIGS. 1A, 2, 7A and 8A illustrate a wand head WH for a wand W,the wand head having at least one aerated foam projecting nozzle NZ forprojecting foam in a substantially focused stream in a roughlyhorizontal direction around an inside tank wall surface. See inparticular FIG. 2 and FIGS. 7A-7F. See also FIGS. 13A-13B and 14 for anembodiment of a wand W including a riser RS and wand head WH.

FIGS. 1A, 2 and in particular FIG. 8B illustrate an ambient air aerationchamber AAAC located upstream of, proximate to, and in fluidcommunication with, at least one aerated foam projecting nozzle NZ.

FIGS. 1A, 2 and in particular 8A, 8D, 8E, 8H and 8I illustrate a nozzleNZ having at least four fins FN in a tip portion TP of the nozzle NZ.The fins FN have a longitudinal dimension LD greater than a radialdimension RD and terminate substantially flush with a nozzle tip TPdischarge orifice DO.

FIGS. 1A, 2, 8A, 8E, 8H and 8I, as well as FIG. 13, illustrate anembodiment of an aeration chamber structured together with a nozzle toproject at least 100 gpm at 100 psi of aerated foam having an expansionof between 2-to-1 to 8-to-1.

FIGS. 2 and 13A-13B illustrate the nozzle NZ and chamber AAAC attachedto a riser RS for communicating water and foam concentrate.

FIGS. 7A-7F, and in particular and FIGS. 13 and 14, illustrate at leastone nozzle and riser structured in combination for attachment to a tankwall of at least 100 foot diameter tank such that the nozzle projectsfoam in a roughly horizontal direction around an interior top tank wallsurface.

FIGS. 1A, 2, 7A, 8A, 13A-13B and 14 show two aerated foam projectingnozzles NZ, the two nozzles structured in combination to project roughlyhorizontally in roughly opposing directions. Roughly opposing directionsshould be taken to mean directly opposite plus or minus 15°. Alternatelystated, each nozzle should project within 15 degrees of 1 common averagelongitudinal axis for the pair of nozzles. A roughly horizontaldirection should be taken to mean within 15° of the horizontal.

FIGS. 1A, 2, 7A-7F, 8A-8M, 13A-13B and 14 also illustrate aerationchambers and a nozzle or nozzles that can be structured to projectaerated foam with an expansion of between 3-to-1 to 5-to-1. FIG. 8Dillustrates a discharge port PT structured in a fluid conduit betweenthe nozzles and an aeration chamber, the discharge port structured todischarge up to 150 gpm of aerated foam predominantly in a directionroughly perpendicular to the said opposing direction.

FIGS. 1A, 2, 7A-7F, 8A-8M, 13A-13B and 14 illustrate a nozzle or nozzlesthat can be structured to project aerated foam at between 100 gpm and900 gpm at 100 psi.

FIG. 15 illustrates a plurality of four wands spaced around a tankperiphery, approximately 190 feet apart.

FIG. 7F illustrates an at least 2 inch riser RS structured to extendfrom proximate a ground location to proximate an at least 45 foot highindustrial top tank wall portion. One of skill in the art knows thatindustrial storage tanks of 60 foot diameter and greater have a wallheight of approximately 45 feet or greater.

FIGS. 9-12 illustrate an at least four inch riser RS, preferablycomprised of riser top portion RTP, riser extension pipe REP, and riserinlet pipe RIP. See FIG. 9. FIG. 10 illustrates a riser foot rest kitfor stabilizing an at least four inch riser RS. FIG. 11G furtherillustrates an at least four inch riser RS. FIG. 12 illustrates riser RSlocated proximate a tank wall. FIGS. 12 and 13 illustrate riser RSlocated proximate a tank wall and structured to extend from proximatethe ground to proximate a tank wall portion. A firefighting nozzlecapable of at least 150 gpm is shown attached to the monitor riser inFIGS. 12 and 13A-13B. The monitor riser is indicated attached to monitorM and nozzle N. It can be seen from FIGS. 12 and 13A-13B that themonitor and nozzle is structured to discharge from proximate the toptank wall, and including an ability to discharge roughly toward thecenter of the tank. Roughly toward the center of the tank should beinterpreted as toward the center of the tank +/−30°.

Again, FIG. 9 illustrates a riser for a portable monitor and nozzle, theriser RS comprised of three sections, RTP, REP and RIP, and structuredto communicate firefighting fluid from proximate a ground location toproximate the top of an at least 45 foot high industrial storage tank,as illustrated by FIG. 13A. A fitting FT is illustrated attached to thedistal end of the riser RS, structured to releasably affix an at least150 gpm portable monitor M and nozzle N. In this case the fitting iscomprised of exterior male threads upon the upper portion of the riserpipe. A removable cap as well as the portable monitor and nozzle willhave mating interior female threads, probably assisted by a pair ofturning ears, to effect quick attachment and release.

FIG. 16 illustrates staging the riser RS with monitor and nozzle at alanding LN of a tank. As is known in the art a ladder is affixed to atank, leading to the landing. FIG. 17 illustrates a typical tank with aladder LD and landing LN.

In operation an aerated foam projecting nozzle would preferably projectaerated foam roughly horizontally in a substantially focused streamaround an inside top tank wall surface of an at least 100 foot diametertank. The nozzle would produce aerated foam having an expansion ofbetween 2-to-1 to 8-to-1. Preferably the foam would have an expansion ofbetween have an expansion of between 3-to-1 to 5-to-1. Preferably twoaerated foam projecting foam nozzles would be included, projectingroughly horizontally in substantially focused streams and in roughlyopposing directions. Preferably the nozzle or nozzles would be affixedto an upper wall portion of an industrial storage tank.

In a point and shoot method, firefighting fluid from approximately theground is also provided to approximately the tank top through an atleast four inch riser located proximate the tank wall, the at least fourinch riser attachable to an at least 150 gpm portable monitor and nozzleby virtue of a fitting on a distal end of the at least four inch riser.Alternately an at least 150 gpm nozzle could be fixedly attached to theat least four inch riser. The fixed nozzle would be structured with theriser to discharge proximate to a tank top wall portion and toward thecenter of the tank. The portable monitor and nozzle can be aimed andturned by a fire fighter.

In the point and shoot method if the at least four inch riser isstructured to releasably attach to a portable monitor and nozzle, thenthe at least four inch riser should be located proximate a landing atthe top of the tank wall. Alternately, if the at least four inch riseris structured to fixedly attach to a firefighting nozzle, then the risercan be located any place around the periphery around the tank includinga plurality of places. The riser and the fixed nozzle would bestructured such that the nozzle discharges roughly toward the center ofthe tank.

FIG. 17 illustrates a typical ladder LD and landing LN of an industrialstorage tank T. FIGS. 18 and 19 provide a table estimating the number offoam wands required for a point and shoot system as a function of theheight of the foam dam of a floating roof. These are the number of foamwands needed for full encirclement seal protection.

The foregoing description of preferred embodiments of the invention ispresented for purposes of illustration and description, and is notintended to be exhaustive or to limit the invention to the precise formor embodiment disclosed. The description was selected to best explainthe principles of the invention and their practical application toenable others skilled in the art to best utilize the invention invarious embodiments. Various modifications as are best suited to theparticular use are contemplated. It is intended that the scope of theinvention is not to be limited by the specification, but to be definedby the claims set forth below. Since the foregoing disclosure anddescription of the invention are illustrative and explanatory thereof,various changes in the size, shape, and materials, as well as in thedetails of the illustrated device may be made without departing from thespirit of the invention. The invention is claimed using terminology thatdepends upon a historic presumption that recitation of a single elementcovers one or more, and recitation of two elements covers two or more,and the like. Also, the drawings and illustration herein have notnecessarily been produced to scale.

What is claimed is:
 1. A fixed firefighting system for industrial tanks,comprising: two connected nozzles, each nozzle structured to projectaerated foam at a flow rate of at least 100 gallon per minute (gpm) at100 pounds per square inch (psi) in substantially focused streams and inroughly opposing directions; the two connected nozzles attacheddownstream of, and in fluid communication with an ambient air aerationchamber; a third centrally directed nozzle structured to project aeratedfoam at a flow rate of at least 100 gpm at 100 psi, located andstructured in combination with the two connected nozzles to discharge asubstantially focused stream toward a center of an industrial tank; astream shaper located in a cylindrical tip portion of the thirdcentrally directed nozzle; and the three nozzles structured for fixedattachment proximate a wall surface of the industrial tank.
 2. Thesystem of claim 1, wherein the third centrally directed nozzle isstructured to project in a horizontal direction plus or minus 30degrees.
 3. The system of claim 1, wherein each of the two connectednozzles are structured to project in the horizontal direction plus orminus 15 degrees.
 4. The system of claim 1, wherein each of the twoconnected nozzles are structured to project in directly oppositedirections plus or minus 15 degrees.
 5. The system of claim 1, whereinthe third centrally directed nozzle is structured to project toward acenter of the industrial tank plus or minus 30 degrees.
 6. The system ofclaim 1, wherein each of the two connected nozzles are structured toproject aerated foam of between 100 gpm and 1000 gpm.
 7. The system ofclaim 1, wherein the third centrally directed nozzle is structured toproject aerated foam of between 100 gpm and 1000 gpm.
 8. The system ofclaim 1, wherein the third centrally directed nozzle is structured toproject such that at least 60% of the foam discharge remains within a 20degree cone around a third discharge axis.
 9. The system of claim 1,wherein the ambient air aeration chamber is structured to produceaerated foam with an expansion ratio of between 2-to-1 and 8-to-1. 10.The system of claim 1, wherein the ambient air aeration chamber isstructured to produce aerated foam with an expansion ratio of between3-to-1 and 5-to-1.
 11. The system of claim 1 including a riser forcommunicating water and foam concentrate, attached to, and in fluidcommunication with the two connected nozzles and the third centrallydirected nozzle.
 12. The system of claim 1, wherein each of the twoconnected nozzles are structured to project aerated foam of at least1100 gpm.
 13. The system of claim 1, wherein the third centrallydirected nozzle is structured to project aerated foam of at least 1100gallons per minute gpm.
 14. A fixed firefighting system for industrialtanks, comprising: a plurality of systems of claim 1, wherein each ofthe plurality of systems are attached proximate the wall surface of theindustrial tank.
 15. A fixed firefighting system for large industrialtanks, comprising: two connected nozzles, each nozzle structured toproject aerated foam at a flow rate of at least 150 gallons per minute(gpm) at 100 pounds per square inch (psi) roughly horizontally and inroughly opposing directions; the two connected nozzles attacheddownstream of, and in fluid communication with an ambient air aerationchamber; a third centrally directed nozzle structured to project aeratedfoam at a flow rate of at least 150 gpm at 100 psi, located andstructured in combination with the two connected nozzles to discharge asubstantially focused stream toward a center of an industrial tank; astream shaper located in a cylindrical tip portion of the thirdcentrally directed nozzle; and the three nozzles structured for fixedattachment proximate a wall surface of the industrial tank.
 16. Thesystem of claim 15, wherein each of the two connected nozzles arestructured to project in the horizontal direction plus or minus 15degrees.
 17. The system of claim 15, wherein each of the two connectednozzles are each structured to project in directly opposite directionsplus or minus 15 degrees.
 18. The system of claim 15, wherein the thirdcentrally directed nozzle is structured to project toward a center ofthe industrial tank plus or minus 30 degrees.
 19. The system of claim15, wherein each of the two connected nozzles are structured to projectaerated foam of between 150 gpm and 1000 gpm.
 20. The system of claim15, wherein the third centrally directed nozzle is structured to projectaerated foam of between 150 gpm and 1000 gpm.
 21. The system of claim15, wherein the third centrally directed nozzle is structured to projectsuch that at least 60% of the foam discharge remains within a 20 degreecone around a third discharge axis.
 22. The system of claim 15, whereinthe ambient air aeration chamber is structured to produce aerated foamwith an expansion ratio of between 2-to-1 and 8-to-1.
 23. The system ofclaim 15, wherein the ambient air aeration chamber is structured toproduce aerated foam with an expansion ratio of between 3-to-1 and5-to-1.
 24. The system of claim 15 including a riser for communicatingwater and foam concentrate, attached to, and in fluid communication withthe two connected nozzles and the third centrally directed nozzle. 25.The system of claim 15, wherein the third centrally directed nozzle isstructured to project in a horizontal direction plus or minus 30degrees.
 26. A fixed firefighting system for industrial tanks,comprising: a plurality of systems of claim 11, wherein each of theplurality of systems are attached proximate the wall surface of theindustrial tank.